Mechanical behavior of stressed films on anisotropic substrates

Abstract

The effects of stressed thin films on substrates that possess anisotropic elasticity have been measured and modeled. Substrate curvature induced by a uniform, stressed film will be axisymmetric for substrates possessing greater than twofold in-plane symmetry, and anisotropic for twofold symmetric substrates. For a (011) Si substrate, the difference between the curvature along the 〈 110 〉 and 〈 100 〉 principal axes varies by approximately 47%. A simple, analytical formulation of the force and moment balance equations for elastically anisotropic films and substrates has been employed to calculate the dependence of curvature and strain on substrate orientation for several cases. © 2008 American Institute of Physics.